AccuWeather makes a bold 30-day leap for travelers

Though it sometimes seems meteorologists can't even predict the next day's weather, AccuWeather has begun taking its longest-range stab at prognostication yet: 30 days.

Among the biggest beneficiaries could be travelers with flexibility in their plans. For instance, should you be planning a weekend escape during the next month but you're not sure when, a 30-day forecast could help steer you to the most favorable weekend.

Or if your two weeks in Spain will include a few nights in the Pyrenees, such a long-range forecast could help narrow down when to book that mountain villa.

Steven Smith, AccuWeather's chief digital officer, said the forecast is based on more than just historical averages; it is made up of data from government agencies and private entities from around the world, then massaged by a team of more than 100 meteorologists, he said.

"We're trying to answer things like, 'When will it turn colder? When will it rain next? — things you won't get from a historical average," Smith said. "The value is in paying attention to the trends."

The predictions can seem bold: for instance, a 15-degree swing in the high temperatures over a 24-hour period more than two weeks down the line. How is such a guess possible?

"To be honest, it is as much an art as a science in meteorology," Smith said. "A lot of it is experience, and a lot of it is the (quality of the data) itself."

He acknowledged that a forecast becomes less reliable the further the guess ventures into the future. But today's weather can help predict the temperatures a month from now, he said.

"The weather today is tied to seeing patterns over a large region — say the upper Midwest or the Northeast or the Southeast," Smith said. "I'll guarantee you it won't be perfect, but the point is to give the users something more than the almanac."

Should a 30-day forecast not be enough to help your travel plans, good news: AccuWeather is working on a 45-day forecast available as a premium service.